Just finished the memoirs of Colonel Napier who was the British military attache to Bulgaria in the run up to WW1.
This is a detailed study of the diplomatic efforts to bring Bulgaria into the war on the side of the Entente. He travelled extensively across the Balkans during this period so you get a good understanding of the position in all the Balkan states.
He describes in some detail his meetings with politicians and military leaders in these countries and the reader gets a good understanding of the factors that resulted in the decisions each country took. He is fairly critical of British foreign policy towards Bulgaria and clearly believed that a firmer line could have brought them into the allied camp.
In the end he was captured by a German submarine when leaving Greece on a passenger boat and spent the rest of the war in a prison camp before being exchanged. He then returned as the military attache to Sophia.
Not a light read this but well worth the effort for anyone interested in the Balkans during WW1.